A, IC50 of PPIs in inhibiting FASN activity derived from dose-response curves (see Figure S1). Lanso, lansoprazole; Ome, omeprazole; Panto, pantoprazole; Rabe, rabeprazole. B, Western blot analysis of FASN expression in different human breast cancer cell lines. 468, MDA-MB-468; 231, MDA-MB-231. C, IC50 of PPIs in inhibiting breast cancer cell survival derived from dose response survival curves (see Figure S2). D, Relative average IC50 of PPIs in all four breast cancer cell lines tested. E, Correlation between PPI IC50 and the level of endogenous FASN in all 4 breast cancer cells shown in panel B.